com.entrust.toolkit.util

Class SecureOutputStreamWriter

java.lang.Object

java.io.Writer

com.entrust.toolkit.util.SecureOutputStreamWriter

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.Appendable, java.lang.AutoCloseable

public class SecureOutputStreamWriter
extends java.io.Writer

Securely writes characters to an output stream, translating characters into bytes according to a specified character encoding.

The encoding used by an instance of SecureOutputStreamWriter may be specified by name. If the encoding is not specified, the default encoding, defined by the system property file.encoding, will be used.

Each invocation of a write method causes the encoding converter to operate on the given characters. The resulting bytes are accumulated in a buffer before being written to the underlying output stream. All temporary data is wiped following its use, and the buffer is automatically wiped after it is written to the OutputStream.

Field Summary

Fields inherited from class java.io.Writer

lock

Constructor Summary

Constructors

Constructor and Description
SecureOutputStreamWriter(java.io.OutputStream out) Creates a SecureOutputStreamWriter object that uses the default character encoding.
SecureOutputStreamWriter(java.io.OutputStream out, java.lang.String enc) Creates a SecureOutputStreamWriter object that uses the specified character encoding.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the underlying OutputStream.
void	flush() Flushes the internal buffer to the OutputStream before flushing the OutputStream itself.
java.lang.String	getEncoding() Returns the name of the character encoding being used by this writer.
void	write(char c) Securely writes a single character to the OutputStream.
void	write(char[] ca, int off, int len) Securely writes a portion of an array of characters to the OutputStream.
void	write(java.lang.String s) This method is not supported.

Methods inherited from class java.io.Writer

append, append, append, write, write, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SecureOutputStreamWriter

public SecureOutputStreamWriter(java.io.OutputStream out)

Creates a SecureOutputStreamWriter object that uses the default character encoding.

Parameters:

out - the output-stream

SecureOutputStreamWriter

public SecureOutputStreamWriter(java.io.OutputStream out,
                        java.lang.String enc)
                         throws java.io.UnsupportedEncodingException

Creates a SecureOutputStreamWriter object that uses the specified character encoding.

Parameters:

out - the output-stream

enc - the character encoding to be used

Throws:

java.io.UnsupportedEncodingException - thrown if the encoding is not supported

Method Detail

close

public void close()
           throws java.io.IOException

Closes the underlying OutputStream.

All data is automatically flushed before the output stream is closed.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in class java.io.Writer

Throws:

java.io.IOException - thrown if the close was unsuccessful

flush

public void flush()
           throws java.io.IOException

Flushes the internal buffer to the OutputStream before flushing the OutputStream itself.

Specified by:

flush in interface java.io.Flushable

Specified by:

flush in class java.io.Writer

Throws:

java.io.IOException - thrown if the flush was unsuccessful

getEncoding

public java.lang.String getEncoding()

Returns the name of the character encoding being used by this writer.

Returns:

the character encoding used by this writer

write

public void write(char c)
           throws java.io.IOException

Securely writes a single character to the OutputStream.

This method converts the character and then writes it to an internal buffer if there is space. If there is not enough space, the buffer and then the converted data are written to the OutputStream. All internal temporary data is wiped before the method returns.

Parameters:

c - the characther to write

Throws:

java.io.IOException - thrown if the write was unsuccessful

write

public void write(char[] ca,
         int off,
         int len)
           throws java.io.IOException

Securely writes a portion of an array of characters to the OutputStream.

The method converts the characters and then writes them to an internal buffer if there is space. If there is not enough space, the buffer and then the converted data are written to the OutputStream.

Note

The input character array ca is not wiped by this method. All internal temporary data is wiped before the method returns. Use the SecureUtils.wipe( char [] ) method to destroy the input character array.

Specified by:

write in class java.io.Writer

Parameters:

ca - the array of characters to write

off - the offset from which to start writing characters

len - the number of characters to write

Throws:

java.io.IOException - thrown if the write was unsuccessful

write

public void write(java.lang.String s)
           throws java.io.IOException

This method is not supported.

Using a String as an argument would create a copy of the data in memory that cannot be destroyed.

Overrides:

write in class java.io.Writer

Parameters:

s - the string to write

Throws:

java.io.IOException